EFFECT OF STEARIC ACID TREATMENT ON THE HYDROPHOBICITY OF ZNO-COATED Styrax tonkinensis WOOD

Abstract

Micro/nanostructure coating is a useful technology that can enhance the hydrophobicity of wood. However, there are not many works studying the effect of treatment condition on the hydrophobicity of coated-wood. In this research, the Styrax tonkiensis wood with superhydrophobic surfaces was obtained by ZnO coating method followed by treating with stearic acid. Surface characteristics of the coating were examined by Field Emission Scanning Electron Microscopes (FE-SEM), Energy-dispersive X-ray Spectroscopy (EDS), X-ray Diffraction (XRD), and water contact angle (WCA). The results showed that the coating on wood was composed of micro/nano-size ZnO sheets with Wurtzite crystal structure. The water contact angle of the coated-wood was significantly larger than that of uncoated-wood. Additionally, with different stearic acid treatment conditions, the water contact angle was not the same. In particular, some coated-wood samples sufaces became superhydrophobic with WCAs greater than 150 degrees. The ZnO coating played the roll in transforming the S. tonkinensis wood from the hydrophilic material into superhydrophobic material with self-cleaning function.